Apparatus for and method of manufacturing spindle components

ABSTRACT

With reference to FIG.  3  the present invention relates to a method of manufacture of a product from a first component ( 4 ) of deformable material and a second component ( 5 ), the-method comprising the steps of:  
     inserting a portion of the first component ( 4 ) through an aperture predefined in the second component ( 5 ); and subsequently  
     deforming the material of the first component ( 4 ) to form a pair of spaced apart shoulders ( 50 ) integral with the first component ( 4 ), the spaced apart shoulders ( 50 ) holding therebetween the second component ( 5 ) and thereby preventing the second component ( 5 ) sliding along the first component ( 4 ); wherein:  
     each shoulder ( 50 ) is formed by applying tool means ( 20, 21 ) to a surface of the first component ( 4 ) to create a recess in the surface and to form the shoulder ( 50 ) adjacent to the recess with the shoulder ( 50 ) being formed by displacement of the deformable material of the first component ( 4 ) during the creation of the recess.  
     The present invention also relates to apparatus for performing the method.

[0001] The present invention relates to apparatus for and a method ofmanufacturing spindles and in particular to a method of rigidly fixingsecondary components such as flanges to a spindle.

[0002] Spindles in the form of cylindrical elongated rods are widelyused in mechanical devices. Spindles may be used to transmit both axialand rotational forces between components of a machine and it is known toprovide secondary components such as keys, keyways, splines and flangeson the spindle to facilitate such force transmission. Spindles may alsocomprise threaded portions and/or undercuts to facilitate attachment ofthe spindle to other components and reaction points such as the chassisin a vehicle. An example of the use of a spindle is as a mounting for aspring means in a vehicle seat adjuster. The spindle is provided with aflange at a point along its longitudinal axis against which one end ofthe spring means abuts. Axial force is transmitted from the spring meansto the spindle (and then onto either a further component or a reactionpoint) through the flange. As can be readily appreciated the jointbetween the flange and the spindle undergoes shear stresses commensuratewith the axial force imparted to the spring means.

[0003] It is known to attach secondary components such as keys andflanges to the central spindle by means of welding or soldering.However, soldering can result in a joint between the secondary componentand the spindle which is too weak to transmit the required forces.Welding, whilst providing a strong joint requires aggressive heating ofthe components which can be deleterious to the strength and hardnessproperties of the spindle and/or flange. Soldering and welding can alsoresult in an unacceptably uneven surface to the secondary component andspindle in the vicinity of the joint and are processes which are labourintensive, slow and expensive to carry out.

[0004] The present invention provides in a first aspect a method ofmanufacture of a product from a first component of deformable materialand a second component, the method comprising the steps of:

[0005] inserting a portion of the first component through an aperturepredefined in the second component; and subsequently

[0006] deforming the material of the first component to form a pair ofspaced apart shoulders integral with the first component, the spacedapart shoulders holding therebetween the second component and therebypreventing the second component sliding along the first component;wherein:

[0007] each shoulder is formed by applying tool means to a surface ofthe first component to create a recess in the surface and to form theshoulder adjacent to the recess with the shoulder being formed bydisplacement of the deformable material of the first component duringthe creation of the recess.

[0008] The present invention provides in a second aspect apparatus forfixedly locating of a first component having a cylindrical portion asecond component having an aperture therein of a diameter chosen suchthat the second component is mountable on, and freely slidable along thecylindrical portion of the first component, the apparatus comprising:freely rotating means for supporting the first component;

[0009] first and second shafts disposed parallel to one another, atleast one of the first and second shafts being movable in a planeperpendicular to its axis in a direction towards the other shaft;

[0010] means for rotating the first and second shafts;

[0011] first and second roller means axially spaced apart positioned oneach shaft, the first and second roller means each having first andsecond inclined surfaces of differing inclinations and the first andsecond inclined surfaces of the first roller means on one shaft havinginclinations which match the inclinations of the first and secondinclined surfaces of the first roller means on the other shaft and thefirst and second inclined surfaces of the second roller means on oneshaft having inclinations which match the inclinations of the first andsecond inclined surfaces of the second roller means on the other shaft;wherein:

[0012] the first and second shafts are moved towards each other toengage the first and second roller means of each shaft with the firstcomponent, with the engagement of the roller means with the firstcomponent generating forces which act to force the first and secondroller means towards each other, such force arising due to the differinginclinations between the first and second inclined surfaces of eachroller means; and the engagement of the roller means with the firstcomponent can deform material of the first component on either side ofthe second component with the forces applied to the first componentforming thereon raised shoulders, the raised shoulders being located onboth sides of the second component and fixedly locating second componenton the first component.

[0013] The present invention provides apparatus for use in an automaticmethod for fixing secondary components, such as flanges, to spindleswithout soldering or welding which results in a joint strong enough totransmit high axial and rotational forces between the spindle andsecondary component and yet does not require external or aggressiveheating of the spindle and/or secondary component.

[0014] The present invention provides a quicker, safer, stronger andmore precise method of jointing secondary components to spindles than isknown in the state of the art.

[0015] Preferred embodiments of the present invention will now bedescribed by way of example only with reference to and as shown in theaccompanying drawings, in which:

[0016]FIG. 1 a front elevation of an apparatus according to a firstembodiment of the present invention;

[0017]FIG. 2 is a cross-sectional elevation taken on line A-A of FIG. 1;

[0018]FIG. 3 is a schematic cross-section of a part of the apparatus ofFIG. 1 in use;

[0019]FIG. 4 is schematic diagram of a part of the apparatus of FIG. 1;

[0020]FIG. 5 is front elevation of an apparatus according to a secondembodiment of the present invention;

[0021]FIG. 6 is a cross-sectional elevation taken on line B-B of FIG. 5;and

[0022]FIG. 7 is cross-sectional side elevation of a further part of theapparatus of FIGS. 1 and 5.

[0023]FIGS. 1 and 2 show a first embodiment of an apparatus according tothe present invention. The apparatus 1 comprises two rotating shafts 3disposed parallel to one another. One of the shafts 3 is on fixedcentres whilst the other shaft is positioned within a hydraulicallyoperated slide (not shown) which allows the shaft 3 to undergocontrolled movement in a direction perpendicular to the axis of theshaft 3 towards the fixed shaft, whilst remaining disposed parallelthereto.

[0024] Each shaft 3 comprises an annular roller mount 14 disposed aroundthe shaft 3. A key 15 formed on the shaft 3 and keyway 16 formed in theroller mount 14 transmit rotational forces between the shaft 3 androller mount 14 and ensure that no relative movement occurstherebetween.

[0025] The roller mount 14 of each shaft 3 comprises on an outer face 17two rollers 20, 21 of generally annular shape. The rollers 20, 21 arespaced apart in the axial direction to produce a gap 22 between innerside faces 23 of the rollers 20, 21. Positioned within the gap 22 is anannular inner plate 12 which is fixed radially relative to shaft 3. Eachroller 20, 21 is mounted within the roller mount 14 such that it isslidable in the axial direction. The inner side face 23 of each roller20, 21 includes a recess 26 in opposition to one another. Spring means13 in form of Belleville washers or die type springs are anchored ineach recess 26 and span between the two rollers 20, 21 to bias therollers 20, 21 apart such that the gap 22 is maximised when theapparatus is in an inoperative condition. The maximum dimension of thegap 22 is adjustable using adjuster nut 31 and this enables the axialstarting position of the rollers 20, 21 to be established. Differentnumbers and types of Belleville washers may be utilised to alter theeffective spring force between the two rollers 20, 21. The annular innerplate 12 provides a limit stop to prevent the rollers 20, 21 from movingtoo close to one another axially to damage the biasing means 13.

[0026] An outer face of the annular rollers 20, 21 forms a rolling face25. The configuration of the rolling face 25 is most clearly shown inFIGS. 3 and 4. Each roller 20, 21 has portions which gradually inclineoutwardly. The rollers 20, 21 also have annular projections 27A and 27Beach of generally triangular shape when viewed in cross-section as shownin FIG. 4. The projections 27A and 27B have relatively steeply inclinedface 28A and 28B (at an α angle to the radial direction) nearest theinner side face 23 of the roller and a shallower inclined face 29A and29B (at an angle β to the longitudinal axis) furthest from the innerside face 23 of the roller. In the preferred embodiment shown in FIGS. 3and 4 α is 45° and β is 9°. In addition the faces 25 have portions 30 ofminimal inclination (at an angle γ to the longitudinal axis and in thepreferred embodiment γ is 1°). The remainder of the faces 25 are rightcylindrical, having a substantially uniform outer diameter.

[0027] The component to be machined is a spindle 4 of elongated,generally cylindrical form. The spindle 4 may comprise recessed and/orraised portions. However the portion of the spindle 4 in the vicinity ofthe area to be machined is cylindrical, having an even outer diameter.Preferably the spindle 4 has an elongation of greater than or equal to12 percent.

[0028] In the preferred embodiment the component to be fixed to thespindle 4 is a washer 5 which has a central aperture of diametermarginally greater than the outer diameter of the cylindrical portion ofthe spindle 4 such that the washer 5 is free to slide along the axis ofthe spindle 4 before being fixed thereto. The outer diameter of thewasher 5 is immaterial to the present invention.

[0029] In use the spindle 4 is positioned between the two shafts 3 suchthat the three longitudinal axes of the two shafts 3 and the spindle 4are component-linear.

[0030] The spindle 4 is supported on a freely rotating rest 40 as shownin FIG. 7. The freely rotating rest 40 comprises a series of rollingbearings 41 in a generally U-shaped trough in which the spindle 4 may bepositioned such that the roller bearings bear at a number of pointsalong the longitudinal length of the spindle 4. The roller bearings 41help to prevent the axis of the spindle 4 being deformed out of trueduring the machining process. The freely rotating rest 40 also includesa freely rotating end stop 43 at one end against which one end of thespindle 4 abuts in use. The freely rotating rest 40 and end stop 43 bothhave the ability to rotate freely in order to accommodate the tangentialforces set up by rolling friction and the combined Polar Moment ofInertia when the spindle 4 and washer 5 come into contact with therollers 20, 21. The rotating end stop 43 is movable in the direction ofthe longitudinal axis of the spindle 4 form a rearwardly extendedposition (in which the spindle 4 may be introduced and removed from theapparatus) to a forwardly extended position.

[0031] The washer 5 to be fixed to the spindle 4 is introduced into theapparatus and positioned and held between the freely rotating rest 40and the inner plates 12 of the roller mounts 14. The washer 5 is alsopositioned axially-on the spindle 4 such that the washer is disposedbetween the inner side faces 23 of the rollers 20, 21.

[0032] The hydraulically operated slide on the movable shaft 3 isoperated to bring the two shafts 3 and pairs of rollers 20, 21 towardsone another causing the rolling faces 25 of each roller 20, 21 tocontact the surface of the spindle 4. The movement of the movable shaft3 on the hydraulic slide is preferably controlled by automated meanssuch as computerised control system of known design.

[0033] The pair of rollers 20 contact the spindle 4 axially to one sideof the washer 5 and the other pair of rollers 21 contact the spindle 4axially on the other side. Due to the low frictional characteristics ofthe freely rotating roller rest 40 and rotating end stop 41, contactbetween the rollers 20, 21 and spindle 4 causes the spindle 4 to rotatesuch that there is no relative tangential movement between the rollingfaces 25 and the spindle surface 4 at the junction. In other words therollers 20, 21 positively rotate the spindle 4 without slippage betweenthe spindle 4 and rolling faces 25.

[0034] Due to its enlarged diameter compared to the remainder of theroller, the extremity of the projection 27 is the first portion of therolling faces 25 of the rollers 20, 21 to contact the spindle surface.Contact of the projection 27 with the spindle 4 results in a force beingapplied to the spindle 4. Due to the steeply inclined 28 and shallowlyinclined 29 faces of the projection 27, on initial penetration of theprojection 27 into the spindle surface the radial force supplied by thehydraulic slide moving the movable shaft 3 creates a force between eachinclined face 28, 29 and the spindle 4 with radial and longitudinalcomponents. Due to difference in angles α and β there is set up adifferential force in the longitudinal direction from each projection 27in the direction of the washer 5. This differential force causes therollers 20, 21 to move towards each other and the washer 5 against thebiasing force of the Belleville springs 13 as the shafts 3 are broughtinto closer proximity. Due to the symmetry of the rollers 20, 21 aboutthe plane of the washer 5 the locus of movement of each of the rollers20, 21 mirror one another. Thus the action of the projection 27 of therollers 20, 21 deforms the material of the spindle in the vicinity ofthe washer 5 both radially and longitudinally to form an identicalraised shoulder 50 on either side of the washer 5. The raised shoulder50 has a diameter greater than that of both the remainder of thecylindrical portion of the spindle and the diameter of the aperture ofthe washer 5. The longitudinal deformation of the material of thespindle is such that the raised shoulder 50 also abuts against the sidefaces of the washer 5. Thus the raised shoulder firmly fixes thelongitudinal position of the washer 5 relative to the spindle 4. Thedeformation can also be great enough to rotationally fix the washer 5relative to spindle 4. The integrity of the rotational fixation of thewasher 5 may be improved by providing surface indentations or serrationsin the side faces of the washer near the aperture edge into whichdeformed material may flow; the deformed material and indentationshaving a keying effect.

[0035] The size of the projection 27 is such that the total volume ofmaterial deformed is slightly greater than the volume of material raisedabove the initial diameter of the cylindrical portion of the spindlenecessary to form the raised shoulder. The small excess of materialdeformed creates a cusp 51 of material adjacent to the side faces of thewasher 5. The cusps so formed prevent the inside side faces 23 of therollers 20, 21 contacting and damaging the side faces of the washer 5.

[0036] The angles α and β may be altered in order to created differentprofiles of raised shoulder and also to alter the magnitude of thedifferential force. The greater the difference between angles α and βthe greater the differential force. It has been found that angle α ispreferably at least four times the magnitude of the angle β to create asufficient differential force. In the embodiment described above angle αequals 45° and angle β equals 9°.

[0037] The minimally inclined parts of surfaces 30 of the roller 20, 21spaces the remainder of the rolling faces apart from the spindlesurface. The remainder of the rolling faces advantageously “irons” outany deformities in the spindle surface remote from the raised shouldercaused by the forming process.

[0038] The presence of identical sets of rollers 20, 21 on both shafts 3means that forces applied to the spindle in the forming process aresymmetrical; no bending moments are imparted on the spindle 4 and noresultant axial forces are experienced by the shafts.

[0039] After formation of the raised shoulders 50 the movable shaft 3 ismoved away from the fixed shaft causing the rollers 20, 20 to return tothere inoperative, spaced apart position under the bias of theBelleville washers 13. The rotating end stop 51 is moved to its rearwardmost position and the finished spindle 4 is removed leaving theapparatus ready to receive the next spindle to be formed.

[0040] The present invention is suitable for precisely positioning thelongitudinal placement of the washer 5 on the spindle 4 since thelongitudinal position of the washer 5 is determined solely by thedistance between the rotating end stop 43 against which one end of thespindle abuts and the centre of the gap 22 between the two rollers 20,21. This distance is consistent and maybe easily calibrated.

[0041] A second embodiment of the present invention is shown in FIGS. 5and 6. The rolling faces 25 of the rollers 20, 21 in the secondembodiment are as described in the first embodiment. In the embodimenthowever, the movement of each roller 20, 21 is positively and separatelycontrolled by hydraulic means. Hydraulic pressure and flow is providedto each shaft 3 through a suitable known connection means such asDeublin rotating distributors. Hydraulic flow is fed to first and secondpiston means 61, 62 through internal conduits 63, 64. Each piston means61, 62 comprises a piston 65 fixedly attached to a roller carrier 66.Each roller carrier 66 is attached to, and moves with one of the rollers20, 21. Thus the piston means 61, 62 is utilised to move the roller 20,21 inwardly towards each other and are biased outwardly by springs suchas spring 100 or such as the Belleville Springs 13 of the firstembodiment. Adjuster nuts 101 establish the axial starting position ofthe rollers 20, 21 which has to be precise relative to the geometry ofthe components and the volume of the shoulders 50 to be rolled. As aconsequence of the use of the piston means 61, 62 each roller 20, 21 maybe moved independently of the other.

[0042] Each roller 20, 21 is of the same general external configurationas in the first embodiment and an annular inner plate 12 is againprovided in the gap 22 between the rollers 20, 21 as a compression limitstop. During the forming process the washer 5 rests against the rollers20, 21 and must not contact the inner plate 12.

[0043] A digital control system of known type controls movement of eachpiston 65 and the hydraulic slide of the moveable shaft 3.

[0044] The piston 65 of the first piston means 61 has a slightly greaterpiston area than the piston 65 of the second piston means 62. In oneaspect of the present invention the first piston means 61 has a pistonarea 2% greater than that of the second piston means 62. Due toidentical hydraulic pressure being fed to each piston means, theincreased area of the first piston means that a marginally greater forceis applied to the spindle 4 by the first piston means 61 than by thesecond piston means 62. This has the effect of ensuring that the spindleis at all times abutted firmly against the rotating end stop 43 sincethe first piston means acts towards the rotating end stop 43.

[0045] The first piston means 61 and corresponding roller 20 are movedlongitudinally under control of the control system such that theprojection 27A moves from position A1 in FIG. 3 to position A2. Movementof the first piston means 61 is limited by shoulder 70 against which theroller carrier abuts. Precise longitudinal positioning of the washer 5on the spindle 4 may thus be ensured by calibrating the distance betweenthe freely rotating end stop 43 and the shoulder 70. The second pistonmeans 62 and roller 21 are operated to move the corresponding projection27B from position B1 to position B2 as shown in FIG. 3. Different forcesarise because of the different piston areas and therefore the secondpiston means 62 reaches its limit of motion after the first piston means61. Advantageously the hydraulic system is used to supplement thedifferential forces set up by the geometry of the projection 27 toprovide an improved forming process.

[0046] The hydraulic system used with the second embodiment comprisestwo independent power sources, controlled by electrically operated servovalves for each shaft 3. The servo valves are controlled by a closedloop electronic amplifier and digital position system. The piston meansare provided with a feedback system working off a volumetric analysergiving square wave output signals which correspond to the hydraulic flowrate to each shaft. In this way the control system can ensure that thecorresponding rollers 20, 21 on each shaft 3 move in precise alignmentso as to avoid imparting any twisting forces on the spindle and/orvibrations to the apparatus. A feedback system on the main hydraulicslide, having a digital encoder with a reference pulse, is used tocomponent-ordinate the timing of the piston means with the movable shaft3.

[0047] The two independent axis controls are linked for relative timingby the reference pulse. The velocity and stroke imparted to the formingrollers 20, 21 ensures a locus of travel along angle β for each of therollers 20, 21 until the final form position A2, B2 is reached.

[0048] The present invention according to the second embodiment has theadvantage of the application of controllable forces, timing and geometryto enable the rollers 20, 21 to be designed to create a raised shoulder50 of any required shear section and diameter. For example, theapplicants have produced a spindle 4 having a thrust washer 5 with ashear section of ≦1.80 mm per side which gives ≦20 Kn of shear strength.The performance of the two pairs of rollers 20, 21 where constructionand operation accuracy ensure close control of concentricity and axialaccuracy of the rollers 20, 21 (≦0.03 per roller at 170 Dia) buildsinherent accuracy into the rolling process. Ongoing SPC data showscapability at ≦0.02 axial runout at 18 Dia on the washer 5 relative tothe diameter of the spindle 4 adjacent to the washer 5.

[0049] Whilst the present invention has been described with reference tojoining an annular washer to a spindle the invention is not limited tosuch. For example the apparatus and method described above may also beadapted for joining non-circular symmetric components to spindles havingat least a cylindrical portion.

1. A method of manufacture of a product from a first component ofdeformable material and a second component, the method comprising thesteps of: inserting a portion of the first component through an aperturepredefined in the second component; and subsequently deforming thematerial of the first component to form a pair of spaced apart shouldersintegral with the first component, the spaced apart shoulders holdingtherebetween the second component and thereby preventing the secondcomponent sliding along the first component; wherein: each shoulder isformed by applying tool means to a surface of the first component tocreate a recess in the surface and to form the shoulder adjacent to therecess with the shoulder being formed by displacement of the deformablematerial of the first component during the creation of the recess.
 2. Amethod of manufacture as claimed in claim 1 comprising the step ofsliding the second component along the first component by the engagementof the second component with one or both shoulders during theirformation, each shoulder being formed in such a way that the secondcomponent is pushed towards the other shoulder with the second componentbeing eventually secured in place in the first component by thesimultaneous engagement of both shoulder.
 3. A method as claimed inclaim 1 wherein the first component is a metal component and the toolmeans used is a metal working tool means.
 4. A method as claimed inclaim 1 wherein the portion of the first component inserted through theaperture in the second component is cylindrical, the aperture in thesecond component is circular and matches in diameter the cylindricalportion of the first component, and the method includes the step ofrotating relative to each other the tool and the first component andeach of the shoulders is formed on the cylindrical portion of the firstcomponent, each shoulder comprising an annular ridge of a diametergreater than the diameter of the remainder of the cylindrical portionand each recess comprising an annular recess extending around thecircumference of the cylindrical portion.
 5. A method as claimed inclaim 4 wherein the first component is a generally cylindrical spindleand the second component is a washer and the method includes the step ofrotating the spindle.
 6. A method as claimed in claim 1 wherein the toolmeans used comprises a tool which has a triangular portion with anopening which is the first point of the tool engaged with the firstcomponent, the triangular point having first and second inclinedsurfaces extending away from the apex at different inclinations, themethod including the steps of applying a force on the tool perpendicularto the surface of the first component whilst allowing the tool to moveparallel to the surface under the influence of the resultant forcegenerated by the interaction of the two differently inclined surfaces ofthe tool with the surface of the first component.
 7. A method as claimedin claim 6 comprising additionally the step of applying a force on thetool which acts tangentially to the surface of the first component andwhich assists in the displacement of material to form both the recessand the shoulder.
 8. A method as claimed in claim 1 wherein the toolmeans comprises a pair of tools and the method comprises the steps of:engaging the pair of tools with the first component, one on either sideof the mounted second component, with each tool forming one shoulder;generating forces on the pair of tools which act both to force the toolsperpendicularly into the surface o the first component and alsotangentially along the surface of the first component towards eachother; and using the tangential forces generated during the formation ofthe shoulders to slide the second component along the first component toa desired location relative to the first component in which the secondcomponent is engaged by both shoulders.
 9. A method as claimed in claim1 wherein the volume of deformable material displaced to form eachrecess is greater than the volume of deformable material forming eachshoulder and the method comprises the step of forming from the excessmaterial cusps adjacent to the second component.
 10. A method as claimedin claim 1, wherein one or more recesses is formed in a surface of thesecond component surrounding the aperture in the second component andthe method includes the step of forcing displaced material of the firstcomponent into the one or more recesses in the surface of the secondcomponent during immediately following formation of the shoulders sothat in the manufactured product the shoulders prevent translation ofthe second component and the engagement of material of the firstcomponent in the recess of the second component prevents relativerotation between the first and second components.
 11. Apparatus forfixedly locating on a first component having a cylindrical portion asecond component having an aperture therein of a diameter chosen suchthat the second component is mountable on, and freely slidable along thecylindrical portion of the first component, and apparatus comprising:freely rotating means for supporting the first component; first andsecond shafts disposed parallel to one another, at least one of thefirst and second shafts being movable in plane perpendicular to its axisin a direction towards the other shaft; means for rotating the first andsecond shafts; first and second roller means axially spaced apartpositioned on each shaft, the first and second roller means each havingfirst and second inclined surfaces of differing inclinations and thefirst and second inclined surfaces of the first roller means on oneshaft having inclinations which match the inclinations of the first andsecond inclined surfaces of the first roller means on the other shaftand the first and second inclined surfaces of the second roller means onone shaft having inclinations which match the inclinations of the firstand second inclined surfaces of the second roller means on the othershaft; wherein: the first and second shafts can be moved towards eachother to engage the first and second roller means of each shaft with thefirst component, with the engagement of the roller means with the firstcomponent generating forces which act to force the first and secondroller means towards each other, such forces arising due to thediffering inclinations between the first and second inclined surfaces ofeach roller means; and the engagement of the roller means with the firstcomponent can deform material of the first component on either side ofthe second component with the forces applied to the first componentforming thereon raised shoulders, the raised shoulder being located onboth sides of the second component and fixedly locating the secondcomponent on the first component.
 12. Apparatus as claimed in claim 11wherein the first and second inclined surfaces of each roller meanstogether define on the roller means an annular region of triangularcross-section.
 13. Apparatus as claimed in claim 11 wherein each of thefirst and second shafts comprises identical first and second rollermeans movable in unison on engagement with the first component so thatno bending moments are imposed on the first component.
 14. Apparatus asclaimed in claim 11, wherein the roller means each have first and secondinclined surfaces configured such that the total volume of material ofthe first component deformed is greater than the volume of materialraised above the diameter of the cylindrical portion of the firstcomponent necessary to form the shoulders such that the excess deformedmaterial forms cusps of material adjacent to the side of the secondcomponent.
 15. Apparatus as claimed in claim 11, wherein the firstinclined surface of each rolling means is relatively steeply inclinedand the second inclined surface of each rolling means is relativelyshallowly inclined.
 16. Apparatus as claimed in claim 11, wherein thefirst inclined surface of each roller means is inclined at approximately45° to the longitudinal axis.
 17. Apparatus as claimed in claim 11wherein the second inclined surface is inclined at approximately 9° thelongitudinal axis.
 18. Apparatus a claimed in claim 11 wherein therolling means further comprises a portion of minimal inclination and aportion of even diameter.
 19. Apparatus as claimed in claim 11 whereinthe first and second roller means are biassed apart form one another inan inoperative state.
 20. Apparatus as claimed in claim 11 whereinbiassed force is a spring means comprising a plurality of Bellevillewashers.
 21. Apparatus as claimed in claim 11 wherein the first andsecond roller means are connected to respective first and second pistonmeans.
 22. Apparatus as claimed in claim 21 comprising hydraulicactuation means for hydraulically actuating the first and second pistonmeans.
 23. Apparatus as claimed in claim 22 wherein the first pistonmeans has a greater piston area than the second piston means and bothpiston means receive hydraulic fluid from a common source at a commonpressure whereby a greater longitudinal component of force is applied tothe first component in the direction of movement of the first pistonmeans than in the direction of the second piston means such that thefirst component is firmly abutted against the rotating end stop. 24.Apparatus as claimed in claim 23 wherein stop means is provided to limitthe motion of the first piston means and fix the exact position of thefirst piston means relative to the rotating end stop.
 25. Apparatus asclaimed in claim 11 wherein the at least one movable shaft is slidableon a hydraulically actuated slide.
 26. Apparatus as claimed in claim 25wherein the hydraulic actuation means connected to the first and secondpiston means and hydraulic slide includes one or more servo valves tocontrol movement of the first and second rollers on each shaft to ensurethat each pair of first and second rollers on the two shaft move inunison.
 27. Apparatus as claimed in claim 11 wherein the freely rotatingrest comprises a substantially U-shaped elongated carrying meansincluding a plurality of roller bearings contactable in use with thefirst component.
 28. Apparatus as claimed in claim 27 wherein the freelyrotating support means comprises a rotating end stop against which anend of the first component abuts.
 29. Apparatus as claimed in claim 28wherein the rotating end stop is movable from a forwardly extendedposition to a rearwardly extended position.
 30. Apparatus as claimed inclaim 11 wherein computer controlled means are provided for controllingactuation of the hydraulically movable slide.